The role of electronic bandstructure shape in improving the thermoelectric power factor of complex materials
arXiv:2311.03935 · doi:10.1021/acsaelm.3c00887
Abstract
The large variety of complex electronic structure materials and their alloys, offer highly promising directions for improvements in thermoelectric (TE) power factors (PF). Their electronic structure contains rich features, referred to as 'surface complexity', one of them being the highly anisotropic warped energy surface shapes with elongated features and threads in some cases. In this work we use Boltzmann transport simulations to quantify the influence that the shape of the electronic structure energy surfaces has on the PF. Using both analytical ellipsoidal bands, as well as realistic bands from the group of half-Heuslers, we show that band shape complexity alone can offer an advantage to the PF of ~3x in realistic cases. The presence of anisotropic scattering mechanisms such as ionized impurity or polar optical phonon scattering, however, can reduce these improvements by up to ~50%. We show that expressions based on the simple ratio of the density-of-states to the conductivity effective masses, mDOS/mC, together with the number of valleys, can capture the anisotropy shape with a moderate to high degree of correlation. For this, we use a convenient way to extract these masses by mapping the complex bandstructures of materials to parabolic electronic structures, without the need for Boltzmann transport codes. Despite the fact that the PF depends on many parameters, information about the benefits of the band shape alone, would be very useful for identifying and understanding the performance of novel thermoelectric materials.
References in corpus (21)
- "Pudding mold" band drives large thermopower in NaCoO
- Topological insulators and thermoelectric materials
- Electron Transport in Silicon Nanowires: The Role of Acoustic Phonon Confinement and Surface Roughness Scattering
- High three dimensional thermoelectric performance from low dimensional bands
- Electronic fitness function for screening semiconductors as thermoelectric materials
- Mobility of 2D materials from first principles in an accurate and automated framework
- Accelerated screening of thermoelectric materials by first-principles computations of electron-phonon scattering
- Atomistic simulations of low-field mobility in Si nanowires: Influence of confinement and orientation
- Significant enhancement of hole mobility in [110] silicon nanowires compared to electrons and bulk silicon
- Band alignment and scattering considerations for enhancing the thermoelectric power factor of complex materials: The case of Co-based half-Heuslers
- Theory of Band Warping and its Effects on Thermoelectronic Transport Properties
- Fermi surface complexity, effective mass, and conduction band alignment in n-type thermoelectric Mg3Sb2-xBix from first principles calculations
- Impact of the scattering physics on the power factor of complex thermoelectric materials
- Material Descriptors for the Discovery of Efficient Thermoelectrics
- On the Calculation of Lorenz Numbers for Complex Thermoelectric Materials
- Large Seebeck effect in the electron-doped FeAs driven by quasi one dimensional pudding-mold type band
- ElecTra Code: Full-Band Electronic Transport Properties of Materials
- Electron and Hole Mobility of SnO2 from Full-Band Electron-Phonon and Ionized Impurity Scattering Computations
- Comparative first-principles study of antiperovskite oxides and nitrides as thermoelectric material: multiple Dirac cones, low-dimensional band dispersion, and high valley degeneracy
- Remarkable thermoelectric performance in BaPdS via pudding-mold band structure and ultralow lattice thermal conductivity
- Effective masses in complex band structures, a code to extract them